A live mussel byssus removing device and a removing method thereof

Abstract

The application discloses a live mussel byssus removing device and a removing method thereof, and is characterized by comprising a water tank, a sieve grid type feed tank with a sieve hole diameter of 10-15 cm is arranged in the water tank, a culture rope for adhering mussels is arranged in the sieve grid type feed tank, a mussel receiving basket is arranged at the top of the inclined side of the water tank, a scraper type chain belt is laid at the bottom of the water tank, one end of the scraper type chain belt extends to the mussel receiving basket, an aeration pipe for simulating the state of sea wave beating is arranged between the bottom of the sieve grid type feed tank and the scraper type chain belt; the byssus removing method comprises the following steps: placing mussels in seawater with a temperature of 30-35 DEG C, a pH of 6.5-7.5 and a salinity of 15-20 ‰, and simulating the state of sea wave beating, the byssus of the mussels falls to the bottom of the scraper type chain belt, is conveyed to a spraying area of the water tank and is sprayed and washed, and a lossless and efficient live mussel byssus removing process is completed; the method has the advantages of simple operation, high efficiency, rapidness and losslessness.

Description

Technical Field

[0001] This invention relates to the field of seafood processing technology, and in particular to a device and method for removing byssal threads from live mussels. Background Technology

[0002] Mussels are attached mollusks that use byssal glands to secrete various byssal proteins to form byssal threads, securing themselves to solid surfaces such as rocks, ship hulls, and cables underwater. This creates a water-resistant bond, allowing them to withstand the erosion of wind and waves. In my country, mussel farming typically employs rope farming. Mussels attach to the farming rope in a string-like fashion through the strong adhesion of their byssal threads. This method offers advantages such as high yield, short cycle, and convenient harvesting.

[0003] Byssal fibers possess high strength and persistent adhesive properties, making byssal removal from mussels a persistent challenge in harvesting, processing, and subsequent survival. Previously, mussel harvesting was generally done manually, a labor-intensive and inefficient method. Patent CN201410204780 invented a method for removing byssal fibers using a 60-70℃ hot water soaking and fiber-removing device; however, this method makes it difficult to control the mussel's ripeness and maintain its viability. Patent CN201811077651.5 invented a mussel byssal fiber cutting device, using an air bladder and byssal fiber bag to cut the mussel's foot, but the pulling force during cutting damages some of the mussel's muscle, reducing its activity. Patent CN 201721148701.5 invented a byssal fiber removal machine using a combination of pulling and cutting, but similarly, this also damages some of the mussel's muscle, reducing its activity and affecting subsequent survival steps. Therefore, there is an urgent need in practical production for an effective, rapid, and non-destructive method for removing mussel byssal fibers. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a simple, efficient, fast and non-destructive device and method for removing byssal threads from live mussels.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: a live mussel byssal silk removal device, including a water tank, wherein a screen-type feed trough with a screen hole with a diameter of 10-15 cm is provided in the water tank, a culture rope for adhering mussels is provided in the screen-type feed trough, a mussel receiving basket is provided outside the top of the inclined side of the water tank, a scraper-type chain belt is laid at the bottom of the water tank, one end of the scraper-type chain belt extends to the mussel receiving basket, and an aeration pipe for simulating the state of ocean waves is provided between the bottom of the screen-type feed trough and the scraper-type chain belt.

[0006] Furthermore, the water tank has an overflow port on its top outer wall and a drain valve at its bottom.

[0007] Furthermore, a spray pipe is provided inside the inclined side top of the screen-type material trough and above the scraper-type chain belt. The spray pipe is connected to a heat exchanger, which is provided with a mixed cold seawater inlet, a steam inlet, and a condensate outlet.

[0008] Furthermore, the air inlet port of the aeration pipe is equipped with an air pump and a check valve.

[0009] Furthermore, the aeration pipe has a large number of small holes facing upwards, with a diameter of 5-10 mm and a spacing of 50-150 mm.

[0010] Furthermore, the distance between the aeration pipe and the screen-type feed trough is 200~300 mm.

[0011] A method for removing byssal threads from live mussels using the aforementioned device includes the following steps: First, seawater with a temperature of 30-35°C, a pH of 6.5-7.5, and a salinity of 15-20‰ is injected into a water tank. Then, the feed trough is kept submerged in seawater. An air pump is turned on, and air flows into the seawater through an aeration pipe to simulate wave action. The live mussels attached to the aquaculture rope spontaneously detach their byssal threads within a short time. The mussels naturally fall to a scraper-type chain at the bottom. The scraper-type chain transports the detached mussels to the spray area of ​​the water tank for spray rinsing. After removing individual mussels with damaged shells, the mussels are temporarily kept in clean, normal seawater for 2 hours to restore their original activity, thus completing a non-destructive and efficient process for removing byssal threads from live mussels.

[0012] Furthermore, the air pump has a gas flow rate of 0.05 to 0.1 cubic meters per second per square meter of water surface area. This is achieved by introducing air into the pipeline, thus simulating ocean waves while simultaneously addressing the dissolved oxygen issue in seawater.

[0013] Furthermore, the screen-type trough is a square screen body with large holes welded together with stainless steel bars, and the nominal diameter of the screen holes is 10-15 cm.

[0014] Compared with the prior art, the advantages of the present invention are as follows: The present invention provides a live mussel byssalinity removal device and method, based on the principle that adult mussels generally do not move in a suitable environment, but will spontaneously detach their byssalinity when external environmental conditions deteriorate or they are stimulated to seek a more suitable place to attach. The breeding ropes attached to the mussels are placed in seawater with a certain temperature, salinity, and pH value. At the same time, the aeration method simulates the beating of waves to create unsuitable habitat conditions for the mussels, forcing them to adopt an "escape mode" when the environmental factors change drastically. The mussels spontaneously detach their byssalinity within 30 minutes. Then, the mussels that have detached their byssalinity are temporarily kept in clean, normal seawater for 2 hours to restore their original activity, thus achieving non-destructive and efficient byssalinity removal and harvesting.

[0015] In summary, the present invention provides a device and method for removing byssal threads from live mussels. By adjusting the pH, temperature, and salinity of the water and simulating ocean waves, the byssal threads are removed quickly. This process is completed spontaneously by the mussels, without the application of external mechanical force. The mussels after byssal thread removal have no muscle damage, retain their intact shape, and are highly active, which helps to extend their freshness and survival time. The investment cost is low, the operation is simple, and the byssal thread removal time is short, the removal efficiency is high, and the mussel body is undamaged. It is particularly suitable for the live storage, transportation, and sale of mussels from the production area to the market. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the live mussel byssal silk removal device of the present invention; the following are the labels in the figure: 1. Water tank, 2. Culture rope, 3. Mussel, 4. Air pump, 5. Aeration pipe, 6. Check valve, 7. Screen-type feed trough, 8. Heat exchanger, 9. Mixed cold seawater inlet, 10. Steam inlet, 11. Condensate outlet, 12. Spray pipe, 13. Overflow port, 14. Drain valve, 15. Mussel receiving basket, 16. Scraper-type chain belt. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. I. Specific Implementation Methods

[0019] A device for removing the three byssal threads from live mussels, such as Figure 1 As shown, the system includes a water tank 1, a screen-type feed trough 7 with a screen hole diameter of 10-15 cm inside the water tank 1, a culture rope 2 for adhering mussels 3 inside the screen-type feed trough 7, a mussel receiving basket 15 outside the top of the inclined side of the water tank 1, a scraper-type chain belt 16 laid at the bottom of the water tank 1, one end of the scraper-type chain belt 16 extending to the mussel receiving basket 15, and an aeration pipe 5 for simulating the state of ocean waves is set between the bottom of the screen-type feed trough 7 and the scraper-type chain belt 16.

[0020] In this specific embodiment, the top outer wall of the water tank 1 is provided with an overflow port 13 and its bottom is provided with a drain valve 14. A spray pipe 12 is provided inside the inclined side of the screen-type material tank 7 and above the scraper-type chain belt 16. The spray pipe 12 is connected to a heat exchanger 8, which is provided with a mixed cold seawater inlet 9, a steam inlet 10, and a condensate outlet 11. An air pump 4 and a check valve 6 are provided at the air inlet port of the aeration pipe 5. The aeration pipe 5 has a large number of small holes facing upwards, with a diameter of 5-10 mm and a spacing of 50-150 mm. The distance between the aeration pipe 5 and the screen-type material tank 7 is 200-300 mm.

[0021] The method for removing byssal threads from live mussels using the above-mentioned device includes the following steps: First, seawater with a temperature of 30~35℃, pH of 6.5~7.5, and salinity of 15~20‰ is injected into the water tank 1. Then, the screen-type feed tank 7 is kept submerged in seawater. The air pump 4 is turned on, and air flows into the seawater through the aeration pipe 5 to form simulated wave impact. The live mussels 3 attached to the aquaculture rope 2 spontaneously detach their byssal threads within a short time. The mussels 3 naturally fall to the scraper-type chain belt 16 at the bottom. The movement of the scraper-type chain belt 16 transports the detached mussels 3 to the spray area of ​​the water tank 1 for spray rinsing. After removing individual mussels 3 with broken shells, the mussels 3 are temporarily kept in clean, normal seawater for 2 hours to restore their original activity, thus completing the non-destructive and efficient process of removing byssal threads from live mussels 3.

[0022] In this specific embodiment, the gas flow rate of the air pump 4 is 0.05~0.1 cubic meters per second per square meter of water surface area. The screen-type feed trough 7 is a square screen body with large holes welded together with stainless steel bars, and the nominal diameter of the screen holes is 10~15 cm.

[0023] II. Application Examples

[0024] The following uses the thick-shelled mussel 3 as an example to demonstrate the spontaneous removal of byssal threads. This process achieves the goal of removing byssal threads while simultaneously realizing good water circulation. The specific operating steps are as follows:

[0025] Mixed seawater at ambient temperature: The seawater and freshwater are mixed in a mass ratio of 1:0.5, the salinity of the seawater is controlled at 19‰, and the pH is adjusted to 7.0. The seawater is heated to 32°C through the mixed seawater inlet and heat exchanger 8 (steam inlet 10, condensate outlet 11). After the mussels 3 that have lost their byssal threads are rinsed through the spray pipe 12, the seawater flows into the water tank 1. Excess mixed seawater is discharged through the overflow outlet 13.

[0026] Mussel 3 flow direction: The harvested mussels 3 and aquaculture rope 2 are initially rinsed with a high-pressure water gun to remove most of the mud, sand and impurities attached to the mussels 3 and aquaculture rope 2, and then spread evenly on the screen-type feed trough 7. After the mussels 3 automatically detach their byssal threads, they sink through the screen-type feed trough 7 onto the scraper-type chain belt 16. The movement of the scraper-type chain belt 16 slowly sends the detached mussels 3 out of the water to the inclined spray area, where they are rinsed by the spray. Individual mussels 3 with shell damage caused by transportation are picked out at the horizontal section. Finally, the mussels 3 are collected in the mussel receiving basket 15 and then transferred to clean, normal seawater for temporary rearing for 2 hours to allow the mussels 3, which have experienced stress reactions due to a series of factors, to recover to their original normal state.

[0027] Airflow: An air blower is installed 200 mm below the screen-type feed trough 7. The air blower has numerous small holes facing upwards, each 10 mm in diameter and spaced 150 mm apart. The air flow rate is 0.1 cubic meters per second per square meter of water surface area. Air is pumped through the air pump 4 and aeration pipe 5, creating continuous turbulence in the water. This simulates ocean waves while simultaneously addressing dissolved oxygen levels in the seawater, preventing mussels 3 from dying due to insufficient dissolved oxygen in turbid water. The aeration pipe 5 is equipped with a check valve 6 to prevent backflow of water when the machine is stopped.

[0028] Under the combined influence of seawater temperature, salinity, pH, and simulated ocean waves, all the mussels 3 hanging on the culture rope 2 detached their byssal threads and sank within 30 minutes. The mussel receiving basket 15 collected over 95% of the mussels 3 that were single (i.e., mussels without byssal threads).

[0029] To address the long-term accumulation of silt and impurities at the bottom of the water tank 1, a drain valve 14 is installed at the bottom of the water tank 1. The drain valve 14 opens periodically to remove as much silt and impurities as possible from the bottom. At the same time, the water level of the entire system is maintained stable through the overflow port 13.

[0030] III. Comparative Experiment

[0031] 1. Effect of temperature on the time of shedding of the three byssal threads in mussels

[0032] Under conditions of pH 7.0, salinity 15‰, and gas flow rate of aeration pump 4 of 0.1 cubic meters per second per square meter of water surface area, the effect of different water temperatures on the byssal shedding time of mussel 3 was studied. The results are shown in Table 1.

[0033] Table 1. Effects of different water temperatures on the shedding time of the three byssal threads of mussels.

[0034] .

[0035] Shellfish are poikilothermic animals with weak thermoregulation capabilities, and their optimal growth temperature is 15-25℃. When mussels are placed in unsuitable hot environments, their byssal threads detach more quickly. Table 1 shows that both high and low temperatures promote the automatic detachment of byssal threads, but from an energy consumption perspective, high temperatures allow for the use of biomass pellet fuel, which is less costly. Furthermore, while the byssal threads detach faster at 38℃, the high temperature also causes a rapid decline in the mussels' activity, which is detrimental to their survival. Therefore, a seawater temperature of 30-35℃ is recommended.

[0036] 2. Effect of pH value on the time of shedding of the three byssal threads of mussels

[0037] Under the conditions of a set temperature of 32℃, a salinity of 15‰, and a gas flow rate of 0.1 cubic meters per second per square meter of water surface area from the air pump 4, the effect of different pH values ​​of the water on the time of byssal shedding of mussel 3 was studied. The results are shown in Table 2.

[0038] Table 2. Effects of different pH values ​​in water on the shedding time of the three byssal threads of mussels.

[0039] .

[0040] The pH value of the environment determines the acid-base balance and blood pH of mussel 3. Under these conditions, mussel 3 can migrate in the shortest possible time. Table 2 shows that pH significantly affects the shedding of byssal threads in mussel 3; lower pH values ​​promote easier shedding. However, excessively low pH values ​​significantly enhance the stress response of mussel 3, reduce its activity, and are detrimental to its survival in the later stages. Therefore, the pH value of seawater should be controlled between 6.5 and 7.5.

[0041] 3. Effect of salinity on the time of shedding of the three byssal threads in mussels

[0042] Under the conditions of a set temperature of 32℃, pH of 7.0, and a gas flow rate of 0.1 cubic meters per second per square meter of water surface area from the aeration pump 4, the effect of different water salinities on the time of byssal shedding of mussel 3 was studied. The results are shown in Table 3.

[0043] Table 3. Effects of different water salinities on the time of byssalinity detachment in mussels.

[0044] .

[0045] Mussel 3 is at the isotonic point within the normal salinity range. Under unsuitable salinity conditions, the osmotic pressure balance within the body is disrupted, promoting the automatic detachment of the byssal threads. Table 3 shows that mussel 3 is relatively well-suited to high salinity, but under low salinity and low osmotic pressure, the byssal thread detachment time is significantly shortened. Of course, the water salinity cannot be too low; studies have shown that when the water salinity is 14‰, the survival time of mussel 3 is only 4-6 hours. Therefore, the seawater salinity should be controlled at 15-20‰ (mixed with freshwater at a mass ratio of 1:0.5-1). In practical operation, both high and low salinity affect the normal metabolism of shellfish. Considering economic cost and ease of operation, this invention uses a lower salinity level, which offers greater advantages.

[0046] 4. Effect of gas flow rate on the time of shedding of the three byssal threads of mussels

[0047] The temperature was set at 32℃, the salinity at 15‰, and the pH at 7.0. The effect of different gas flow rates of the air pump 4 on the time of byssal silk detachment of mussel 3 was studied. The results are shown in Table 4.

[0048] Table 4. Effect of different gas flow rates of air pump 4 on the time of byssal shedding of mussel 3.

[0049] .

[0050] As shown in Table 4, the gas flow rate of the air pump 4 is more suitable when it is 0.05 to 0.1 cubic meters per second per square meter of water surface area.

[0051] The foregoing description is not intended to limit the invention, nor is the invention limited to the examples given. Any changes, modifications, additions, or substitutions made by those skilled in the art within the scope of the invention should also be considered within the protection scope of the invention.

Claims

1. A method for removing byssal threads from live mussels, characterized in that: A live mussel byssal silk removal device is employed. The device includes a water tank containing a screen-type feed trough with sieve holes of 10-15 cm in diameter. A cultivation rope for adhering mussels is placed inside the screen-type feed trough. A mussel receiving basket is located outside the top of the inclined side of the water tank. A scraper-type chain is laid at the bottom of the water tank, with one end extending to the mussel receiving basket. An aeration pipe simulating wave action is installed between the bottom of the screen-type feed trough and the scraper-type chain. An overflow outlet is located on the top outer wall of the water tank, and a drain valve is located at its bottom. A spray pipe is installed inside the top of the inclined side of the screen-type feed trough, above the scraper-type chain, and connected to a heat exchanger. The exchanger is equipped with a mixed cold seawater inlet, a steam inlet, and a condensate outlet. The method includes the following steps: First, seawater with a temperature of 30~35℃, a pH of 6.5~7.5, and a salinity of 15~20‰ is injected into the water tank. Then, the screen-type feed tank is kept submerged in seawater. The air pump is turned on, and air flows into the seawater through the aeration pipe to form simulated wave impact. The live mussels attached to the aquaculture rope spontaneously detach their byssal threads within a short time. The mussels naturally fall to the scraper-type chain at the bottom. The movement of the scraper-type chain transports the detached mussels to the spray area of ​​the water tank for spray rinsing. After removing individual mussels with damaged shells, the mussels are temporarily kept in clean, normal seawater for 2 hours to restore their original activity, thus completing the non-destructive and efficient process of removing byssal threads from live mussels.

2. The method for removing byssal threads from live mussels according to claim 1, characterized in that: The air inlet of the aeration pipe is equipped with an air pump and a check valve.

3. The method for removing byssal threads from live mussels according to claim 1, characterized in that: The aeration pipe has a large number of small holes facing upwards, with a diameter of 5-10 mm and a spacing of 50-150 mm.

4. The method for removing byssal threads from live mussels according to claim 1, characterized in that: The distance between the aeration pipe and the screen-type feed trough is 200-300 mm.

5. The method for removing byssal threads from live mussels according to claim 1, characterized in that: The gas flow rate of the air pump is 0.05 to 0.1 cubic meters per second per square meter of water surface area.

6. The method for removing byssal threads from live mussels according to claim 1, characterized in that: The screen-type feed trough is a square screen body with large holes welded together with stainless steel bars, and the nominal diameter of the screen holes is 10-15 cm.

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